The present invention relates to machinery for shaping the surface of log workpieces.
Fixed diameter wood logs with longitudinal cove cuts and transverse saddle cuts are a popular building material for the construction of log homes. Conversion of irregular log workpieces into such uniform logs in a single pass of a machine is desirable from an economic standpoint.
A number of machines have been developed in the past for performing various operation on logs.
U.S. Pat. No. 4,168,675 to Chisum shows a machine for preparing logs for log houses which performs an initial shaping operation to form a cylindrically shaped log from a rough log by rotating it about its axis past a rounding cutter. The carriage is then removed to a starting position, and tongue and groove cutters are used to provide a longitudinal groove. The log is then clamped to a table in a fixed position while saddle notches are cut in its surface.
U.S. Pat. No. 3,791,430 to Hood et al again shows a machine utilizing a rotating log which is cut down to a finished surface by a cutter which is driven along the frame of the machine. In a separate cutting operation, a cove cut or longitudinal groove is cut into the leg while it is held in a non-rotating position. Saddle cuts are made transverse to the log after separate shaping and cove cutting operations are completed.
U.S. Pat. No. 4,303,111 to Neville shows a cutting device for forming a smooth cylindrical surface on a rough log. Neville does not show an entire machine, but does show a machine utilizing a rotating cutting head. No cove cutting or saddle cutting apparatus is shown in the Neville patent.
U.S. Pat. No. 3,848,647 to Fell utilizes two chipping heads for rough and finished chipping of a log into a smooth form. After that operation is completed, the log is lifted to an adjacent slide trough to receive a longitudinal groove and transverse slots. A saddle cut is separately made using a different machine. Fell U.S. Pat. No. 3,802,474 shows apparatus for making saddle cuts in logs.
U.S. Pat. No. 3,718,167 to Cervenak is directed to a limb stub cutting mechanism for removing bark and limbs from a log.
U.S. Pat. No. 4,067,368 to Beecroft shows a device for shaping cabin logs which make the cove and saddle cuts, but does not perform any continuous shaping operation on the surface of the log itself. The log must be rotated 180-degrees to make both of the shaping operations on the surface of the log.
In addition to the patents discussed above, the following patents may be of some interest or pertinence to the invention described and claimed herein:
______________________________________ U.S. Pat. No. Patentee ______________________________________ 3,276,492 Kervefors 3,016,931 Brunkow et al 3,540,498 Woloveke 4,167,964 Paris Jr. et al 2,987,085 Porter 2,800,932 Scott 3,538,963 Adams 3,538,964 Warrick 3,880,036 Yokoyama 3,885,483 Ikeya et al 3,583,450 Gunnerman 3,686,990 Margolien 3,343,519 Chapman et al 3,913,644 Braun ______________________________________